It served with the United States military from 1964-1998, and with NASA until 1999. The SR-71 had been developed from the A-12 OXCART (no relation to the A-12 Avenger), a single-seat plane capable of making high-speed recon runs as well.

It was thought satellites and drones could replace the SR-71. The problem was that satellites are predictable, and too many drones just don’t have the performance or reliability. But Lockheed’s Skunk Works, which created the A-12/YF-12/SR-71 family, is now developing a SR-72, and they promise it will be faster than the Blackbird.

Lockheed noted that the SR-71 was designed on paper with slide rules. Even without the benefit of high-technology, the SR-71 proved to be superb at its role.